Vietnamese swimmer tackles 12km upstream swim in Hanoi river with rare dolphin kick
A Vietnamese swimmer has completed an unusual 12.1-kilometer swim against the strong current of Hanoi's Red River using a technique known as dolphin kicking on the back, in what is believed to be a first-of-its-kind feat in Vietnam.
Le Trong Kien poses with the sports watch that recorded his 12km upstream dolphin-kick swim in Hanoi's Red River on October 20, 2026. Photo: Ngoc Khanh / Tuoi Tre
Le Trong Kien, a veteran open-water swimmer from Hanoi, completed the grueling challenge on Tuesday morning, covering 12.1 kilometers from Long Bien Bridge to Thang Long Bridge in five hours, one minute, and 52 seconds.
Unlike conventional backstroke, which uses alternating arm strokes and flutter kicks, dolphin kicking on the back relies on rhythmic, wave-like movements of the body and simultaneous leg kicks to propel the swimmer forward.
Maintaining this physically demanding technique over such a long distance, particularly against the Red River's strong current, made the achievement especially challenging.
Kien's sports watch and fitness-tracking applications recorded an average pace of two minutes and 30 seconds per 100 meters, with the performance data available for public verification.
He undertook the challenge alone, accompanied by his son and fellow swimming enthusiasts on three stand-up paddleboards.
Kien's sports watch displays data from his 12km upstream dolphin-kick swim in the Red River. Photo: Supplied
Most of the journey was livestreamed by Nguyen Ngoc Khanh, an accomplished Vietnamese open-water swimmer who swam 200 kilometers from Hanoi's Long Bien Bridge to the coast of Thai Binh in three days in 2020.
Khanh, who has participated in long-distance swimming adventures around the world, said he was unaware of anyone internationally completing a comparable upstream swim using the same technique.
He described Kien's achievement as an extraordinary feat requiring decades of training, exceptional discipline, and advanced swimming skills.
Le Trong Kien practices dolphin kicking on his back during a training session. Photo: Supplied
Kien is a familiar name in Vietnam's recreational and adventure swimming community, having spent years tackling long distances in rivers, lakes, and the sea.
Before 2021, he helped administer a long-distance swimming club whose members regularly attempted swims ranging from several kilometers to several dozen kilometers.
Outside the water, Kien runs a computer business on Ly Nam De Street in Hanoi. He trains regularly at Quan Thanh Swimming Pool in Ba Dinh Ward.
In December 2020, he completed a five-kilometer dolphin-kick swim on his back in a swimming pool, taking three hours.
Speaking to Tuoi Tre (Youth) about the technique several years ago, Kien recalled experiencing severe back fatigue and abdominal muscle pain when he first began practicing it.
Years of training over progressively longer distances eventually prepared him for Tuesday's ambitious upstream challenge.
His latest performance is being hailed as a remarkable achievement within Vietnam's recreational swimming community.
Although no comparable feat has previously been documented in Vietnam, Kien's accomplishment remains an unofficial record, with no formal certification from a national or international sporting authority.
What is dolphin kicking on the back?
Dolphin kicking on the back is a swimming technique in which swimmers lie face-up and propel themselves forward through rhythmic, wave-like movements of the torso, hips, and legs.
The technique can be performed at the water's surface or underwater and is commonly used by competitive swimmers to improve propulsion, body control, and core strength.
Several Olympic swimmers, including Americans Rick Carey and David Berkoff and Japan's Daichi Suzuki, have used underwater dolphin kicks on their backs to gain speed during races.
However, their use of the technique primarily involved short underwater distances, rather than prolonged swimming in open water.
While dolphin kicking on the back is well established in competitive swimming, its continuous use over long distances in open water is far less documented.
Le Trong Kien's 12.1-kilometer upstream swim therefore stands out as an unusual feat of endurance, although it has not been officially recognized as a world record.
Ngoc Nguyen - Khuong Xuan / Tuoi Tre News
Link nội dung: https://news.tuoitre.vn/vietnamese-swimmer-tackles-12km-upstream-swim-in-hanoi-river-with-rare-dolphin-kick-103261020193202132.htm